Air-compressor.



T. 0. PERRY.

AIR OOMPBESSOB. APPLICATION rlnnn me. 29, 1904.

Patented Oct, 20, 1908.

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WITNESSES.

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THOMAS O. PERRY, OF CHICAGO, ILLINOIS.

AIIVCOMPRESSOR.

Specification of Letters Patent.

Patented Oct. 20, 1908.

Application filed August 29, 1904. Serial No. 222,653.

To all whom it may concern:

Be it known that I, THOMAS, O. PERRY, a citizen of the United States, residing at No. 1025 Park avenue, Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Air-Oompressors, of which the following is a specification.

This invention relates to improvements in air compressors and pumps to be operated by variable power and more especially by wind power and to utilizing energy which is largely wasted in the ordinary use of windmills.

An ideal condition for utilizing wind power in pumping might be realized if the diameter of the piston could be made to change in the same proportion that the velocity of wind changes, or if, without changing diameter of piston, the length of stroke could be made to vary as the square of the winds velocity.

The main object of my invention is to effect, without actually changing the diame: ter of the piston or the length of the stroke, by positive mechanism a variation in the quantity of work per stroke of an air compressor or pump so that a windmill operating the same may within limits carry a load which shall automatically vary to correspond approximately with the changing force of the wind.

Figure 1, is an elevation showing in general on a reduced scale the windmill with compressor attached and a portion of the supporting tower; Fig. 2, is a plan of the head or cap of the air compressor. Fig. 3 is a sectional elevation of the air compressor on the line 33 of Fig. 2. Fig. 4, is a plan of the plunger packing showing the plunger in section. Fig. 5, is an exterior side elevation of the compressor with vent regulator attached viewed in the same direction as Fig. 3. Fig. 6, is an exterior front elevation of the air compressor with vent regulator shown partly in section. 'Fig. 7, is a front elevation of the compressor head with a modified form of the vent regulator attached.

Similar letters refer to similar parts throughout the several views.

The compressor cylinder, E, has exterior flanges both at its upper and lower ends. The cap, 0, is secured to the upper end of the cylinder by screws entering the upper flange. The plunger, F, fits the interior of cylinder, E, loosely, is closed at its upper end, protrudes from the lower end of the cylinder and carries at its lower extremity a cross-head, G.

Plunger rods, G rigidly connect the crosshead with the drive-head, G which is adapted to reciprocate above the cap, O, andis centrally connected to the actuating rod, r, of the windmill. This actuating rod, r, the windmill, B, D, K, P, R, S, V, and the supporting pipe, A, are the same as fully shown and described in my pending application for patent for windmill No. 102,608, filed April 12, 1902. A supporting plate, A, is secured to the lower end of the pipe, A, which supports the windmill at its upper end. Supporting guide rods, C pass loosely through the drive-head and rigidly connect the cylinder cap, C, to the supporting plate, A.

Surrounding the plunger and drawn to the lower cylinder flange by screws is a clamping ring, N, having an interior flan e underneath loosely fitting the plunger, ant inclosing together with the cylinder end an annular packing space. An elastic cylindrical packing, Q, exteriorly flanged on its under side surrounds and presses against the plunger within the annular space. A acking ring, 72, is interposed between the cyhnder end and the exterlor flange of the acking so that it binds the packing flange y tightening the clamping screws. Between the upper portions of the acking, Q, and packing ring, a, is a thin annu ar recess adapted to receive packing-springs, g, which react between the packing-ring and elastic packing. These packingsprings are preferably arranged in two annular layers one within the other and each layer made up of several thin flat spring sections. Four spring sections are shown in each layer in Fig. 4. The spring sections are all under tension. In the outer layer the ends of the spring sections ress outward against the clampingring whi e their centers press inward against the ends of the spring sections in the inner layer which in turn press against the elastic packing throughout their length by reason oftheir proper form before insertion and the superior stiffness of the outer spring sections. These s ring sections may all be nearly straight be ore being sprung into the annular recess, or they may be curved before insertion as suits best the tensions required when in place. The acking may be made of leather or other yielding material. The up or side of the clam ing ring, N, loosely inclbses an annular shou der on the end of the cylinder of the same external diameter as the packing-ring, n. The

. annular packing space is also adapted to receive other forms of packing such as are oridi-l narily used.

The cross-head, G, is not rigidly connected to the plunger, F, but is merely guided loosely in its open lower end and is carried rigidly by a tie rod, L, whose upper end connects with a safety valve, L, which seats against and is guided in the up er closed head of the plunger. A powe ul safety spring, M, surrounding the tie rod, reacts between the olosed head of the plunger and the cross-head so as to hold the safety-valve closed. The safety spring should have sufficient tension to drive the lunger without yielding a ainst any norma resistance, but is designed to yield to abnormal resistance such as might result from accidental clogging of the outlet or undue compression of air, so as to relieve the excessive pressure by letting the safety-valve open. A very slight lifting of the safety-valve lets compressed air pass sufficiently to avoid dangerous pressure.

In the cylinder head is a check' valve, J, opening outward, covered by a cap, 0, from which the outlet or delivery pipe, 0, rises.

The intake valve, H, opens inward and is carried by and rests against a hollow cage, C", Which screws into the cylinder head to one side of the outlet. The guiding stem of the intake valve reaohesup through the center of the cage and terminates in a knob, H, attached so as to form a shoulder beneath which a helical spring H coiled around the stem and resting 1n a recess of the cage reacts to balance the weight of the valve more or less. The under side of the knob, H, is guided in the recess and its upper part is enlarged so as to limit the vertical movement of the intake valve. Around the periphery of the cage are openings for the passage of air.

As so far described, the compressor is com plete for ordinary working, that is for taking in and discharging at each stroke a quantity of air equal to the area of the plunger multiplied by the length of stroke.

It remains to describe devices whereby the compressor is made to discharge into the delivery pipe varying quantities of air per stroke when the actuating power might otherwise be overtaXed.

The contact lever, T, is hinged at one end to an adjustable fulcrum, U, movable vertically or parallel with the direction of the plungers reciprocating motion. Between its extremities the contact lever is adapted to rest upon the knob H, so as to prevent the intake valve closing. The other free end of the contact lever extends to within range of a catch, G carried by the drive head, G, so that it may be engaged and lifted by the catch during the up or compressing stroke of the plunger. The intake valve is thus held open during the plungers up stroke until permitted to close when the contact lever is ifted by the catch. A round Weight, T,

forms an enlargement of the contact lever where it rests on the knob. The free end of the contact lever will be elevated or deressed as the fulcrum is depressed or raised. bo the closing of the intake valve will occur earlier or later during the compression stroke according as the position of the fulcrum, U, is higher or lower. In order that the position of the fulcrum may be automatically adjusted to requirements, it is suspended from a regulating piston, W, loosely fitting the regulating tube, V, closed at its upper end and secured to the supporting plate, A, by a neck, V, at its lower end. Passing loosely through the neck of the regulating tube is the suspending rod, U, which unites the fulcrum, U, with the regulating piston, W. The lower end of the suspending rod, where the fulcrum is clamped on by means of a screw, is made G, towards the end of each up stroke of the plunger, so that the regulating piston and fulcrum may be raised to their upper limit of movement at the end of each compressing stroke.

As shown in figs. 5 and 6, the movement of the regulating piston and fulcrum is limited to about one quarter the length of stroke given to the plunger. Within this limit of movement the regulating piston, W, descends by gravitation at a rate made practically uniform by reason of the partial vacuum formed above and the restriction to the flow of air past the loose fitting piston. The rate of the fulcrums downward motion may be regulated by the fit of the piston in the regulating tube. The fulcrum may settle to the limit of its downward movement if sufficient time elapses between the commence ment of the down stroke of the plunger, F, and the completion of three quarters of its. up stroke, as shown; in which case air will freely escape by the intakevalve during three quarters of the plungers up stroke, since the catch, G is so placed that it will not sooner lift the contact lever, T, and let the intake valve close when the fulcrum, U, is at the limit of its movement downward. If thefulcrum, for want of time during quick strokes of the plunger, does not reach the limit of its downward movement, the intake valve will be closed earlier during the compressing stroke, and the quicker the stroke the earlier will it close until the fulcrum may settle so little that the contact lever will not rest on the knob at all and a full cylinder of air will be compressed at each stroke.

If the compressor be of such proportions that the windmill is properly loaded when com ressing one quarter of its capacity per stro e in one velocity of wind, say eight miles; per hour, it would require that full capacity of air per stroke should be compressed in wind of double velocity, or sixteen miles per hour, in order that the load may also best suit the greater wind velocity. This condition is realized in the construction shown in liigs. 5 and 6, if for the one wind the adjustment is such that the full downward motion of the regulating piston, W, is reached at the moment when the compressing plunger, l has completed of its up StlOiIB. Then in wind of double velocity, slnce piston speed is doubled and compression should begin with the commencement of the up stroke, the regulating iston has time to settle only 3/ 10 as far as before. So the contact lever and catch are arranged to let the intake-valve close when the compressor plunger is at its lowest position and the fulcrum is at 3/ 10 of its whole movement down. By means of an adji. sting screw, and a by-pass, closed more or less by the screw, the rate of the regulating pistons descent may be increased or diminished.

A relief-valve, u, covering ports, in the regulating piston, W, allows air to pass freely only when the piston is forced up by the spur, G but this relief valve may be dispensed with since the regulating piston is sufficiently loose to let air pass quite freely around its periphery when forced up, although its descent by action of gravitation is relatively slow.

The above described intake regulating mechanism provides for closing the intakevalve when the plunger has completed of its compressing stroke, if the closing is not effected sooner. But the wind may weaken so much that its power becomes insufficient to force out even the minimum quantity of air which may be entrapped; in which case it is better to have the intake-valve remain open during the entire up stroke, in order that the windwheel, unresisted during the one stroke, may gain momentum to compress on the next or some succeeding stroke, or, so that, in case the wind-wheel stops on account of wind failure, it may start again unloaded by the com ressor. To this end a latch, H carried by t 1e intake-valve, H, has an end sloping upward and placed in the path of the travehng fulcrum, U, so that it may be pushed thereby under a spur, G on one of the guide-rods, C and hold the intakevalve open in case the fulcrum reaches the extremities of its downward movement, and not otherwise. A flexible cam,'G carried by the drive-head, G, is adapted to disengage the latch from under the spur at each down stroke, unless interfered with by extreme settling of the fulcrum. The latch, H is formed on one end of a bent wire, which passes through the valve knob, H, and extends beyond so as to stop against the other guide-rod and limit its unlatching movement.

The intakeregulating mechanism, as already described, involves a contact arm or lever shiftable with respect to the intake valve and a catch connected with the plunger so as to have corresponding reciprocating motion. Obviously a ike result may be obtained by making the catch shiftable with respect to the plunger and having the contact arm conform only to the motion of the intake-valve. Also other means than a loose re ulating piston may be used for shifting eit er the contact arm or the catch with respect to parts with which they are oper atively connected.

The shifting movement of either contactarm or catch must be of a different character from the regular motion of the parts with reference to which the shifting relates. A shifting movement adjustable with reference to the proper movement of either the plunger or intake-valve may be obtained by means of centrifugal weights driven either directly or indirectly by wind power. Such a device is illustrated in Fig. 7 in which the shifting mechanism is carried by the drive-head, G, and the catch, g, shifts relatively to the plunger. A centrifugal governor of ordinary type has weights, Z, pivoted to a revoluble shaft, X, stepped in an extension, G, of the drive-head, G. The upper end of the gov ernor shaft, X, is made square and is adapted to slide lon itudinally through a sleeve, y, fitting loose y thereon and which revolves as a journal in a bearing held by the bracket, A extending from the supporting pipe, A. A sheave, y, attached to the upper end of the journal, y, may serve for imparting rotary lnotion to the governor shaft by means of a belt or other connection with the windmill. Or the governor shaft, X, may be driven by a se arate horizontal windmill attached direct y to the governor shaft. As shown, the horizontal wind-wheel consists of four hemispherical cups, Y, carried by four arms, Y, radiating from the governor shaft, X, in the manner of ordinary anemometers. Links, 2, connect the centrifugal weights, Z, with a swivel ada ted to revolve upon and move longitudina ly a slide-head, g guided on the governor shaft and carrying the catch arm, 9. A guide rod, g attached to the catch arm parallel with and at some distance from the governor shaft passes loosely through the extension, G, of the. drive-head and prevents rotation of the catch, g, terminating the catch arm. The catch arm is extended and bent so that its cylindrical end, 9, comes in line with the axis of the intake-valve, H. The contact arm in this case is forked, the two forks, t, being somewhat elastic and extending some distance up from the valve knob, H, to which they are attached so as to straddle the cylindrical catch, g, without touching except at their tips, which have beveled spurs facing each other with separating intervals somewhat less than the diout contact sufficient to close the intake valve, which in this case is normally held open by gravitation.

It is evident that the governor will revolve with greater or less rapidity, according to the wind, and that the position of the catch, 9, with reference to the plunger, F, will be more remote as the wind increases in velocity, with consequent earlier closing of the intakevalve. The catch, 9, in high wind, may shift far enough to close the intake at the very beginning of the compressing stroke and in lower winds may close the intake after the plunger arrives within variable distances of the end of its stroke, which distances may vary all the way from that of full stroke to nothing. The adjustment of the shifting intake governor depends on its relative speed of revolution, the proportion and arrangement of its various parts and upon such resistances to its centrifugal action as are ordinarily provided in governors of this character. The ad'ustment should be such that the intake will close at the beginning of the compressing stroke in some determined velocity of wind, and at half that wind velocity the intake should not close until the plunger completes g of its compressing stroke. This form of the shifting intake governor is more especially adapted to use with power windmills or such as transmit their power through a vertical revolving shaft instead of by a reciprocating rod, and is just as adaptable to shifting the contact arm with reference to the intake valve as to shifting the catch relatively to the plunger. Fig. 7 shows the drive-head, G, in its lowest position and the catch, 9, so placed by the governor as to encounter the contact spurs and close the intake when the plunger completes g of its compressing stroke.

Another form of shifting intake regulator is shown in Fig. 1. The forked contact arm, t, and the bent catch arm, g, terminating in a cylindrical catch, g, are the same in form and operation as described above and shown in Fig. 7; but the shifting of the catch relatively to the plunger in this case is accomplished in one direction by gravitation whose action is retarded by the inertia of masses in great part counterbalancing each other through distribution on a pivoted lever fulcrumed between its ends. The fulcrum is on a standard, G carried by an extension, G of the drive-head. The pivoted re ulating lever, w, carries on one side of the fu crum a mass, to, and the catch arm, 9, suspended from its end by a link, while from its other end on the other side of the fulcrum hangs a mass, e0 suspended by a rod, w which passes loosely through a fixed arm, C extending from the compressor head, C. The catch arm, g, is guided vertically on the fulcrum standard and also by a pendent guide rod loosely passing through the drive-head extension, G. The catch arm, 9, and other parts composing the mass on one side of the fulcrum overbalance the mass on the other side, so that the catch settles down whenever gravitation is free to act. The catch is restored during the last quarter of the plungers compressing stroke to its highest position by engagement of the mass, w with the fixed arm, C, at intervals of variable duration depending on the velocity of wind. A stop on the rod, w limits the upward move ment of the catch. In light wind the catch will have time to settle nearer to the drivehead or plunger than in strong wind and will close the intake-valve later in the stroke as the wind becomes weaker.

In order that the intake may close so as to give the most efficient load in Winds of different velocities, adjustments may be made by changing the relative moments of the counterbalancing masses and by altering the length of the contact arm, 15. This device also can be substituted for the regulating piston, W, to shift the position of the fulcrum, U.

Obviously the fulcrum, U, might be clamped upon the fixed guide rod, C in stead of upon the movable suspending rod, U, at any desired height and changed at Will from time to time to suit varying winds or varying resistances to any applied power, and thus serve the same purpose that might, with much greater inconvenience, be accomplished by using at different times various sizes of compressors or pumps or by changing the lengths of their strokes to suit changing conditions of power or work.

The above described devices for retaining the vent or intake valve open during part of the compressing stroke serves also the purpose of moderating the interior temperature of the compressor which, on account of the heat generated in compressing air, reduces efficiency and may seriously interfere with the proper lubrication and maintenance of the plunger packing.

Water cooling of the cylinder is not gener ally convenient in the class of work for which this air compressor is designed; so air cooling becomes an important consideration. The vent or intake closing device enables a much larger compressor to be used than would otherwise be possible without overloading the wind mill or other actuating motor. This permissible enlargement of the compressor in itself furnishes an amount of radiating surface greatly increased in proportion to the average of work performed, since it is only during the higher velocities of the ever varying wind that the compressor works to its full capacity, and during the frequent periods of reduced wind velocities a large amount of fresh air is taken in and expelled, without compression, serving thus to cool the interior of the cylinder where cooling is most needed. -The substitution of a long plunger for the ordinary piston, and making the plunger hollow, serves further to increase the radiating surface. The use of the long plunger also enables the lunger packing to be placed at the cool end of the cylinder farthest from the head where the greatest heat is generated, thus rendering feasible the use of flexible packing material, such as leather, which otherwise might be burned out by the heat of compression.

While this invention is especially applicable to air compressors actuated by wind power, it may also apply to pum s for forcing other fluids, and may be use to advantage in connection with actuating motors other than windmills. For example, when any kind of motor capable of carrying a certain constant load is unevenly loaded at intervals with other work, such as sawing wood or cutting fodder, this air compressor might, at the same time, be operated advantageously, because the air compressor could be so adjusted as to automatically compress more or less air per stroke, according to the variations of motor power unconsumed by other work. When the other work might sufiice to retard the motor to minimum speed desired, the intake would not close at all, and at a maximum of desired speed, when the load due to other work might be greatly reduced, full cylinders of air might be compressed.

Air thus compressed may be stored in reservoirs for any desired purpose and es-' pecially for raising water by means of the device shown in my pending application for patent for pneumatic pump, Serial N umberv 203,228, filed April 14, 1904.

What I claim as my invention, and desire to secure by Letters Patent, is

l. The combination with a windmill and an air compressor having a plunger with connected parts to which reciprocating motion is imparted by the windmill, of a vent valve by which air may escape during a portion of the compressing stroke, vent closing mechanism operative through contact with a reciproeating part, and means whereby the time of said contact may be varied so that the vent may be closed after the plunger arrives withinvarying distances of the end of its compressing stroke, which distances vary with and are determined by the rate of the winds velocity, substantially as herein set forth.

2. The combination with a windmill and an air compressor having a plunger with connected parts to which reciprocating motion is imparted by the windmill, of a vent valve by which air may escape during a portion of the compressing stroke, vent controlling mechanism operative through contact with a reciprocating part, and means whereby said operative contact occurs when the plunger arrives within varying distances of the end of its compressing stroke, said varying distances corresponding to variations in the velocity of the wind, substantially as herein set forth.

3. The combination with a windmill and an air compressor having a plunger with connected parts to which reciprocating motion is imparted by the windmill, of a vent valve by which air may escape during a portion of the compressing stroke, of a vent valve normally adapted to close, mechanism adapted to hold open and to retard the closing of the vent valve during part of the compressing stroke of the plunger, and means whereby said retarding mechanism releases said vent valve when the plunger arrives within varying distances of the end of its compressing stroke, said distances being greater or less-as the wind velocity increases or diminishes, substantially as herein set forth.

4. The combination with a windmill and an air compressor having a cylinder and a reciprocating plunger operated by said windmill, of an intake-valve through which air may also escape during a portion of the plungers compressing stroke, and intake controlling mechanism whereby the closing of said intake-valve may be delayed until the plunger has arrived within variable distances from the end of its compressing stroke which distances vary with and are determined by the rate of the winds velocity, substantially as herein set forth.

5. The combination with a windmill and an air compressor having a cylinder and a plunger operated by the windmill, of an intake valve in the head of said cylinder through which air may also escape during a portion of the plungers compressing stroke, and intake controlling mechanism whereby the closing of said intake-valve may be delayed until the plunger arrives within varying distances of the end of its compressing stroke which distances vary with and are determined by the rate of the winds velocity, substantially as herein set forth.

6. The combination with a windmill and an air compressor having an intake-valve, a cylinder and a reciprocating plunger operated by said windmill, of mechanism whereby said intake-valve may be held open during part of the plungers compressing stroke, and a releasing device to let the intake-valve close after the plunger arrives within variable distances of the end of its compressing stroke which distances vary with and are determined by the rate of the winds velocity, sub stantially as herein set forth.

7. The combination with a windmill and an air compressor having a plunger with con nected parts to which rec'i rocating motion is imparted by the windmill of a vent valve by which air may escape during a portion of the COHIPI'GSSJZIIQLSlJIOkQ aIId mechanism to control the closing of said vent valve earlier or later in the compressing stroke of the plunger accordingly as the velocity of the wind increases or diminishes, substantially as herein set forth.

, 8. The combination with a windmill and an air compressor having an intake-valve, an outlet valve, a c linder and a reciprocating plunger operated by said windmill, of a retaining lever resting between its extremities upon said intake valve to hold it open during part of the plungers compressing stroke, afulcrum at one end of said retaining lever movable in a direction parallel with the plungers motion, a catch reciprocating with the plunger and adapted to engage the other end of said retaining lever so as to release and close the intake valve during some part of the plungers compressing stroke depending on the position of said fulcrum at the time of engagement, and mechanism for automatically adjusting the fposition of said fulcrum so that at the time 0 engagement between said lever and said catch the intake valve may be closed after the plunger arrives within variable distances from the end of its compressing .stroke, which distances will vary with and be controlled by the rate of the rotation of the wind wheel, substantially as herein set forth.

9. The combination with a windmill and an air compressor having a plunger with connected parts to which reci rocating motion is im arted by the windmi l, of a vent valve by w ich air may escape during a portion of the compressing stroke, vent closing mechanism ordinarily operative at variable distances of the plunger from the end of its compressing stroke, and means whereby the vent valve may be locked and held open during the whole of the compressing when the motion of the windmill becomes excessively slow, substantially as herein set forth.

1(). The combination with a windmill and an air compressor having a plunger with connected parts to which recilprocating motion is imparted by the windmi of a vent valve by which air may escape during a portion of the compressing stroke, a vent closing lever operative through contact with a recipro eating part, and a movable fulcrum to said lever whereby said contact may be adjusted to close the vent valve at varying distances of the plunger from the end of the com ressing stroke, substantially as herein set forth.

11. The combination with a windmill and an air compressor having a plunger with connected parts to which reci rocating motion is im arted by the windmill of a vent valve by w iich air may escape during a portion of the compressing stroke, a vent closing lever operative through contacts with a reciprocating part, a movable fulcrum to said lever, and means whereby the position of said ful crum is adjusted automatically through the action of the windmill, so that the vent valve may be closed when the plunger arrives at varying distances from the end of its compressing stroke, substantially as herein set forth.

12. The combination with a windmill and an air compressor having a plunger with connected parts to which reci rocating motion 1 is im arted by the windmi of a vent valve by w ich air may escape during a portion of the compressing stroke, and vent closing mechanism operative by contacts between two moving parts relatively adjustable, one of which parts partakes of motion in con: formity with the-motion of the windmill, while the other moving part receives motionin part through the action of gravitation,

whereby the action of said closing mechanism is timed to close said vent valve when the plunger arrives at greater or less. distances from the end of its compressing stroke accordingly as the wind increases or diminishes in velocity, substantially as herein set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

THOMAS O. PERRY.

Witnesses: 5 v

PEARL R. KEMP, E. B. JUDD. 

